Three-axis magnetic sensor and manufacturing method thereof

Abstract

The present application discloses a three-axis magnetic sensor and a manufacturing method thereof, the three-axis magnetic sensor includes a substrate on which at least two grooves are formed, a first magnetic sensing mechanism for sensing a magnetic field in a first direction, a second magnetic sensing mechanism for sensing a magnetic field in a second direction, and a third magnetic sensing mechanism for sensing a magnetic field in a third direction, the first magnetic sensing mechanism and the second magnetic sensing mechanism are disposed on the surface of the substrate, the third magnetic sensing mechanism is disposed in the grooves, and at least one pair of adjacent grooves is separated by at least one first magnetic sensing mechanism and / or at least one second magnetic sensing mechanism. According to the present application, the process machining error can be reduced, the process window can be widened, and the overall yield of the product can be improved.

Description

[Technical Field]

[0001] The present application belongs to the field of microelectronic technology and relates to a magnetic sensor, and more particularly to a three-axis magnetic sensor and a method for manufacturing the same. [Background technology]

[0002] Conventional three-axis magnetic sensors have separate bridge resistors for X, Y, and Z, with the X-axis and Y-axis sensing units located on a plane and the Z-axis sensing unit on a slope. However, the concentrated distribution of the slope poses great difficulties for process control.

[0003] In view of this, there is currently an urgent need to design a new three-axis magnetic sensor to overcome at least some of the above-mentioned drawbacks of conventional three-axis magnetic sensors. Summary of the Invention

[0004] The present application provides a three-axis magnetic sensor and a manufacturing method thereof, which can reduce process fabrication errors, increase the process window, and improve the overall yield of the product.

[0005] To solve the above technical problems, according to one aspect of the present application, the following technical solution is used.

[0006] The three-axis magnetic sensor includes a substrate whose surface portion is recessed to form at least two grooves, at least one first magnetic detection mechanism that detects a magnetic field in a first direction, at least one second magnetic detection mechanism that detects a magnetic field in a second direction, and at least two third magnetic detection mechanisms that detect a magnetic field in a third direction, wherein the first direction and the second direction form a plane corresponding to the surface of the substrate, and the third direction intersects with the surface of the substrate, and each of the grooves is arranged side by side along the first direction or the second direction, or is arranged side by side partially along the first direction and partially along the second direction, the first magnetic detection mechanism and the second magnetic detection mechanism are installed on the surface of the substrate, and each of the third magnetic detection mechanisms is installed within the grooves so as to correspond one-to-one to each of the grooves, and among the grooves arranged side by side along the first direction, at least one pair of adjacent grooves is separated by at least one first magnetic detection mechanism, and / or among the grooves arranged side by side along the second direction, at least one pair of adjacent grooves is separated by at least one second magnetic detection mechanism.

[0007] As one embodiment of the present application, the first magnetic detection mechanism includes at least one first magnetic resistance strip extending in the second direction, the second magnetic detection mechanism includes at least one second magnetic resistance strip extending in the first direction, and the third magnetic detection mechanism includes at least one third magnetic resistance strip installed on the side wall of the corresponding groove, and each of the third magnetic resistance strips extends along the first direction or the second direction, or extends partially along the first direction and partially along the second direction.

[0008] In one embodiment of the present application, a pseudo-magnetic resistance strip is provided between the adjacent first and third magnetic resistance strips without a Wheatstone bridge, and / or a pseudo-magnetic resistance strip is provided between the adjacent second and third magnetic resistance strips without a Wheatstone bridge.

[0009] In one embodiment of the present application, set / reset coils for generating a magnetic field in the direction of the easy axis of magnetization are arranged above and / or below each of the magnetic resistance strips, and working electrodes are arranged on the upper and / or lower surfaces of the magnetic resistance strips, forming a predetermined angle with the magnetic resistance strips.

[0010] In one embodiment of the present application, the direction of current flow on the magnetoresistive strip is at an angle of 45° to the easy axis of magnetoresistive strip.

[0011] In one embodiment of the present application, each of the magnetic detection mechanisms is combined to form an independent Wheatstone bridge, each arm of each Wheatstone bridge is composed of at least one magnetic resistance strip, several magnetic resistance strips having the same induction change upon sensing an external magnetic field constitute the arms of one Wheatstone bridge, and one Wheatstone bridge includes two sets of arms whose resistance value increases in response to the input of an external magnetic field, and two sets of arms whose resistance value decreases in response to the input of an external magnetic field.

[0012] In one embodiment of the present application, a self-detection coil is disposed in a partial region to generate a magnetic field in a detection direction corresponding to the magnetoresistive strip in response to the magnetic field detected by the magnetoresistive strip.

[0013] According to another aspect of the present application, the following technical solution is used: A method for manufacturing a three-axis magnetic sensor includes the steps of: setting a silicon substrate or a substrate having a circuit; and forming at least two grooves on a surface of the substrate, the sidewalls of which form a predetermined angle with the surface of the substrate, the grooves being arranged side by side along a first direction or a second direction, or being arranged partly along the first direction and partly along the second direction, and a mounting space being provided between at least a pair of adjacent grooves among the grooves arranged side by side in the first direction, and / or a mounting space being provided between at least a pair of adjacent grooves among the grooves arranged side by side in the second direction, and the first and second directions being different from each other. The method includes the steps of forming a plane corresponding to a surface of a substrate, forming an insulating layer on the surface of the substrate and the groove, forming a first magnetic detection mechanism and a second magnetic detection mechanism on the surface of the insulating layer of the substrate, and forming a third magnetic detection mechanism on the surface of the insulating layer of the groove, wherein at least one first magnetic detection mechanism is installed in an mounting space along a first direction and / or at least one second magnetic detection mechanism is installed in an mounting space along a second direction, and wherein all of the first magnetic detection mechanism, the second magnetic detection mechanism and the third magnetic detection mechanism include a magnetic material.

[0014] As an embodiment of the present application, the manufacturing method further includes the steps of forming a dielectric layer on the surface of the magnetic material of the first magnetic sensing mechanism, the second magnetic sensing mechanism, and the third magnetic sensing mechanism; forming through-holes in the dielectric layer on the surface of the magnetic material; forming a continuous electrode layer on the surface of the substrate and on sidewalls of the grooves; and patterning the electrode layer to form a working electrode on the surface of the magnetic material, so that the magnetic material contacts the later-formed working electrode through the through-holes formed in the dielectric layer on its surface.

[0015] In one embodiment of the present application, the magnetic material is any one selected from an anisotropic magnetoresistive material, a giant magnetoresistive material, and a tunneling magnetoresistive material, and when forming the magnetic material, a magnetic field is simultaneously applied to the substrate and annealed to induce the magnetization direction of the magnetic material and enhance the magnetic properties of the magnetic material.

[0016] As one embodiment of the present application, the manufacturing method further includes the steps of providing lead terminals on the surface of the substrate and at both ends of the magnetoresistive strip in the groove, respectively; providing a self-detection coil at the bottom of the groove, below the substrate, and below the magnetic detection mechanism; and providing a set coil and / or a reset coil at the top of the groove, above the substrate, and above the magnetic detection mechanism.

[0017] The beneficial effect of the present application is that the three-axis magnetic sensor and the manufacturing method thereof provided in the present application can reduce process machining errors, widen the process window, and improve the overall yield of the product. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a partial cross-sectional view of a conventional three-axis magnetic sensor. [Figure 2] 1 is a partial cross-sectional view of a three-axis magnetic sensor according to an embodiment of the present application. [Figure 3] 1 is a schematic plan view of a three-axis magnetic sensor according to an embodiment of the present application. [Figure 4] FIG. 10 is a schematic plan view of a three-axis magnetic sensor according to another embodiment of the present application. [Figure 5] FIG. 10 is a schematic plan view of a three-axis magnetic sensor according to another embodiment of the present application. [Figure 6] 1 is a connection schematic diagram of an X-axis magnetic detection mechanism according to an embodiment of the present application forming a Wheatstone bridge. [Figure 7] 1 is a connection schematic diagram of a Y-axis magnetic sensing mechanism according to an embodiment of the present application forming a Wheatstone bridge; [Figure 8] 1 is a connection schematic diagram of a Z-axis magnetic sensing mechanism according to an embodiment of the present application forming a Wheatstone bridge. [Figure 9] FIG. 10 is another connection schematic diagram in which the Z-axis magnetic sensing mechanism according to an embodiment of the present application forms a Wheatstone bridge. DETAILED DESCRIPTION OF THE INVENTION

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] In order to better understand the present application, the following examples are used to describe preferred embodiments of the present application, which are merely intended to further illustrate the features and advantages of the present application and are not intended to limit the scope of the claims of the present application.

[0021] The description in this section is only about some typical embodiments, and the present application is not limited to the scope of the description of the embodiments. The substitution of the same or similar conventional technical means and some technical features in the embodiments is also within the description and protection scope of the present application.

[0022] The description of steps in each embodiment in the specification is for convenience of explanation only, and the implementation method of the present application is not limited to the order of steps. In the specification, "connection" includes both direct connection and indirect connection. In the specification of the present application, "plurality" means two or more.

[0023] The present application discloses a three-axis magnetic sensor, and Fig. 2 is a schematic cross-sectional view of a three-axis magnetic sensor according to an embodiment of the present application. The three-axis magnetic sensor includes a substrate, at least one first magnetic sensing mechanism, at least one second magnetic sensing mechanism, and at least two third magnetic sensing mechanisms.

[0024] Each of the first magnetic sensing mechanisms senses a magnetic field in a first direction, each of the second magnetic sensing mechanisms senses a magnetic field in a second direction, and each of the third magnetic sensing mechanisms senses a magnetic field in a third direction.

[0025] The first and second directions form a plane corresponding to the surface of the substrate, and the third direction intersects with the surface of the substrate.

[0026] The surface portion of the substrate is recessed to form at least two grooves 4. The grooves 4 are all arranged side by side along the first direction or the second direction, or some are arranged side by side along the first direction and some are arranged side by side along the second direction.

[0027] The first magnetic detection mechanism and the second magnetic detection mechanism are installed on the surface of the substrate, and each of the third magnetic detection mechanisms is installed in the groove 4 so as to correspond one-to-one to each groove 4 (i.e., one third magnetic detection mechanism is installed in one groove 4).

[0028] Here, among the grooves 4 arranged side by side in the first direction, at least one pair of adjacent grooves 4 is separated by at least one first magnetic detection mechanism, and / or among the grooves 4 arranged side by side in the second direction, at least one pair of adjacent grooves 4 is separated by at least one second magnetic detection mechanism.

[0029] For example, when there are three grooves 4 arranged side by side in the first direction, they constitute two pairs of adjacent grooves 4. At least one first magnetic detection mechanism is provided between the first pair of adjacent grooves 4 to separate the first pair of adjacent grooves 4, and / or at least one first magnetic detection mechanism is provided between the second pair of adjacent grooves 4 to separate the second pair of adjacent grooves 4.

[0030] Furthermore, for example, when there are three grooves 4 arranged side by side in the second direction, they constitute two pairs of adjacent grooves 4. At least one second magnetic detection mechanism is provided between the first pair of adjacent grooves 4 to separate the first pair of adjacent grooves 4, and / or at least one second magnetic detection mechanism is provided between the second pair of adjacent grooves 4 to separate the second pair of adjacent grooves 4.

[0031] By separating at least one pair of adjacent grooves 4 using at least one first magnetic detection mechanism and / or at least one second magnetic detection mechanism, it is not necessary to concentrate and make the at least one pair of grooves 4 continuous, thereby reducing the difficulty of process control.

[0032] In one embodiment, the grooves 4 arranged in the first direction have at least one first magnetic sensing mechanism provided between each pair of adjacent grooves 4 to separate adjacent grooves 4. The grooves 4 arranged in the second direction have at least one second magnetic sensing mechanism provided between each pair of adjacent grooves 4 to separate adjacent grooves 4.

[0033] In one embodiment, the grooves 4 arranged in the first direction have one first magnetic sensing mechanism between each pair of adjacent grooves 4 to separate the adjacent grooves 4. The grooves 4 arranged in the second direction have one second magnetic sensing mechanism between each pair of adjacent grooves 4 to separate the adjacent grooves 4.

[0034] The first magnetic sensing mechanism includes at least one first magnetoresistive strip extending in the second direction, i.e., the axial direction of the first magnetoresistive strip coincides with the second direction. When the first magnetic sensing mechanism includes at least two first magnetoresistive strips, the first magnetoresistive strips are arranged side by side in the first direction. In one embodiment, the first magnetic sensing mechanism includes two first magnetoresistive strips.

[0035] The second magnetic sensing mechanism includes at least one second magnetoresistive strip extending in a first direction, i.e., the axial direction of the second magnetoresistive strip coincides with the first direction. When the second magnetic sensing mechanism includes at least two second magnetoresistive strips, the second magnetoresistive strips are arranged side by side in the second direction. In one embodiment, the second magnetic sensing mechanism includes two second magnetoresistive strips.

[0036] The third magnetic detection mechanism includes at least one third magnetoresistive strip installed on the side wall of the corresponding groove 4. Among the third magnetoresistive strips, those installed in the grooves 4 arranged in the first direction extend in the second direction, i.e., the axial direction of the third magnetoresistive strip coincides with the second direction. Among the third magnetoresistive strips, those installed in the grooves 4 arranged in the second direction extend in the first direction, i.e., the axial direction of the third magnetoresistive strip coincides with the first direction. The arrangement direction of the third magnetoresistive strips coincides with the corresponding groove 4. All of the third magnetoresistive strips may be arranged in the first direction or the second direction, or some may be arranged in the first direction and some in the second direction. In one embodiment, the third magnetic detection mechanism includes two third magnetoresistive strips. When the third magnetic detection mechanism is installed in grooves 4 arranged in the first direction, the two third magnetoresistive strips are located on both side walls of the groove 4 facing each other in the first direction. When the third magnetic detection mechanism is installed in the grooves 4 arranged side by side in the second direction, the two third magnetoresistive strips are located on both side walls of the groove 4 that face each other in the second direction.

[0037] In one embodiment of the present application, the first direction is perpendicular to the second direction, and the third direction is perpendicular to a plane formed by the first direction and the second direction.

[0038] In one embodiment, the first direction is the X-axis direction of the coordinate system, and the first magnetic sensing mechanism is X-axis magnetic sensing mechanism 1. The second direction is the Y-axis direction of the coordinate system, and the second magnetic sensing mechanism is Y-axis magnetic sensing mechanism 2. The third direction is the Z-axis direction of the coordinate system, and the third magnetic sensing mechanism is Z-axis magnetic sensing mechanism 3.

[0039] The X-axis magnetic sensing mechanism 1 senses a magnetic field in the X-axis direction and includes at least one X-axis magnetoresistive strip, and the Y-axis magnetic sensing mechanism 2 senses a magnetic field in the Y-axis direction and includes at least one Y-axis magnetoresistive strip.

[0040] The Z-axis magnetic detection mechanism 3 is installed on the side wall of the groove 4 and detects a magnetic field in the Z-axis direction. The Z-axis magnetic detection mechanism 3 includes at least one Z-axis magnetoresistive strip, and each Z-axis magnetoresistive strip extends entirely along the X-axis direction or the Y-axis direction, or partially along the X-axis direction and partially along the Y-axis direction.

[0041] In addition, in order to avoid magnetic field interference in the X-axis and Z-axis directions (i.e., to avoid interference between adjacent X-axis magnetic resistance strips and Z-axis magnetic resistance strips), a pseudo magnetic resistance strip 123 without a Wheatstone bridge may be further installed between adjacent X-axis magnetic resistance strips and Z-axis magnetic resistance strips, extending in at least one easy magnetization direction (e.g., the Y-axis direction).

[0042] In order to avoid magnetic field interference in the Y-axis and Z-axis directions (i.e., to avoid interference between adjacent Y-axis and Z-axis magnetic resistance strips), at least one pseudo-magnetic resistance strip 123 extending in the easy magnetization direction (e.g., the X-axis direction) without a Wheatstone bridge interposed therebetween may be further installed between adjacent Y-axis and Z-axis magnetic resistance strips.

[0043] FIG. 3 is a schematic plan view of a three-axis magnetic sensor according to an embodiment of the present application. As shown in FIGS. 3 and 2, the X-axis magnetic sensing mechanism 1 includes a plurality of first X-axis magnetoresistive strips 1a and / or a plurality of second X-axis magnetoresistive strips 1b, each of which extends in a corresponding easy magnetization direction (e.g., the Y-axis direction). The first X-axis magnetoresistive strips 1a increase their resistance in response to an external magnetic field, while the second X-axis magnetoresistive strips 1b decrease their resistance in response to an external magnetic field. Specifically, in this embodiment, there are two types of X-axis magnetic sensing mechanisms 1: the first X-axis magnetic sensing mechanism includes two first X-axis magnetoresistive strips 1a, and the second X-axis magnetic sensing mechanism includes two second X-axis magnetoresistive strips 1b.

[0044] The Y-axis magnetic detection mechanism 2 includes a plurality of first Y-axis magnetoresistive strips 2a and / or a plurality of second Y-axis magnetoresistive strips 2b, each extending in a corresponding easy magnetization direction (e.g., the X-axis direction). The first Y-axis magnetoresistive strips 2a increase their resistance in response to an external magnetic field, while the second Y-axis magnetoresistive strips 2b decrease their resistance in response to an external magnetic field. Specifically, in this embodiment, there are two types of Y-axis magnetic detection mechanisms 2: the first Y-axis magnetic detection mechanism includes two first Y-axis magnetoresistive strips 2a, and the second Y-axis magnetic detection mechanism includes two second Y-axis magnetoresistive strips 2b.

[0045] The Z-axis magnetic sensing mechanism 3 includes a plurality of first Z-axis magnetoresistive strips 3a and / or a plurality of second Z-axis magnetoresistive strips 3b, each extending in a corresponding easy magnetization direction (e.g., a portion in the X-axis direction and a portion in the Y-axis direction). The first Z-axis magnetoresistive strips 3a increase in resistance in response to an external magnetic field, while the second Z-axis magnetoresistive strips 3b decrease in resistance in response to an external magnetic field. Specifically, in this embodiment, there are three types of Z-axis magnetic sensing mechanisms 3: the first Z-axis magnetic sensing mechanism includes two first Z-axis magnetoresistive strips 3a, the second Z-axis magnetic sensing mechanism includes two second Z-axis magnetoresistive strips 3b, and the third Z-axis magnetic sensing mechanism includes one first Z-axis magnetoresistive strip 3a and one second Z-axis magnetoresistive strip 3b.

[0046] As shown in FIG. 3, the grooves 4 are arranged in a row, partly in the X-axis direction and partly in the Y-axis direction.

[0047] Among the grooves 4 arranged in parallel in the X-axis direction, an X-axis magnetic detection mechanism 1 may be installed between adjacent grooves 4. For example, a first X-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4, and a second X-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4. Alternatively, a Z-axis magnetic detection mechanism 3 may be installed in the grooves 4. For example, a first Z-axis magnetic detection mechanism may be installed in some of the grooves 4, a second Z-axis magnetic detection mechanism may be installed in some of the grooves 4, and a third Z-axis magnetic detection mechanism may be installed in some of the grooves 4. Specifically, the first X-axis magnetic detection mechanism is located between the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. The second X-axis magnetic detection mechanism is located between the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. In the third Z-axis magnetic sensing mechanism, the first Z-axis magnetoresistive strip 3a is adjacent to the first X-axis magnetic sensing mechanism, and the second Z-axis magnetoresistive strip 3b is adjacent to the second X-axis magnetic sensing mechanism. The first Z-axis magnetoresistive strip 3a and the second Z-axis magnetoresistive strip 3b in the corresponding groove 4 extend in the Y-axis direction, and each of the first X-axis magnetoresistive strips 1a and each of the second X-axis magnetoresistive strips 1b extend in the Y-axis direction. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent first X-axis magnetoresistive strip 1a and first Z-axis magnetoresistive strip 3a. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent second X-axis magnetoresistive strip 1b and second Z-axis magnetoresistive strip 3b.

[0048] Among the grooves 4 arranged in parallel in the Y-axis direction, a Y-axis magnetic detection mechanism 2 may be installed between adjacent grooves 4. For example, a first Y-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4, and a second Y-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4. Alternatively, a Z-axis magnetic detection mechanism 3 may be installed in the grooves 4. For example, a first Z-axis magnetic detection mechanism may be installed in some of the grooves 4, a second Z-axis magnetic detection mechanism may be installed in some of the grooves 4, and a third Z-axis magnetic detection mechanism may be installed in some of the grooves 4. Specifically, the first Y-axis magnetic detection mechanism is located between the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. The second Y-axis magnetic detection mechanism is located between the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. In addition, in the third Z-axis magnetic sensing mechanism, the first Z-axis magnetoresistive strip 3a is adjacent to the first Y-axis magnetic sensing mechanism, and the second Z-axis magnetoresistive strip 3b is adjacent to the second Y-axis magnetic sensing mechanism. The first Z-axis magnetoresistive strip 3a and the second Z-axis magnetoresistive strip 3b in the corresponding grooves 4 extend in the X-axis direction, and each of the first Y-axis magnetoresistive strips 2a and each of the second Y-axis magnetoresistive strips 2b extend in the X-axis direction. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent first Y-axis magnetoresistive strips 2a and 3a. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent second Y-axis magnetoresistive strips 2b and 3b.

[0049] 4 is a schematic plan view of a three-axis magnetic sensor according to another embodiment of the present application. As shown in FIG. 4, in this embodiment, the grooves 4 are arranged in parallel in the Y-axis direction.

[0050] Among the grooves 4 arranged in parallel in the Y-axis direction, a Y-axis magnetic detection mechanism 2 may be installed between adjacent grooves 4. For example, a first Y-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4, and a second Y-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4. Alternatively, a Z-axis magnetic detection mechanism 3 may be installed in the grooves 4. For example, a first Z-axis magnetic detection mechanism may be installed in some of the grooves 4, a second Z-axis magnetic detection mechanism may be installed in some of the grooves 4, and a third Z-axis magnetic detection mechanism may be installed in some of the grooves 4. Specifically, the first Y-axis magnetic detection mechanism is located between the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. The second Y-axis magnetic detection mechanism is located between the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. In addition, in the third Z-axis magnetic sensing mechanism, the first Z-axis magnetoresistive strip 3a is adjacent to the first Y-axis magnetic sensing mechanism, and the second Z-axis magnetoresistive strip 3b is adjacent to the second Y-axis magnetic sensing mechanism. The first Z-axis magnetoresistive strip 3a and the second Z-axis magnetoresistive strip 3b in the corresponding grooves 4 extend in the X-axis direction, and each of the first Y-axis magnetoresistive strips 2a and each of the second Y-axis magnetoresistive strips 2b extend in the X-axis direction. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent first Y-axis magnetoresistive strips 2a and 3a. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent second Y-axis magnetoresistive strips 2b and 3b.

[0051] 5 is a schematic plan view of a three-axis magnetic sensor according to another embodiment of the present application. As shown in FIG. 5, in this embodiment, the grooves 4 are arranged in parallel in the X-axis direction.

[0052] Among the grooves 4 arranged in parallel in the X-axis direction, an X-axis magnetic detection mechanism 1 may be installed between adjacent grooves 4. For example, a first X-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4, and a second X-axis magnetic detection mechanism may be installed between some of the adjacent grooves 4. Alternatively, a Z-axis magnetic detection mechanism 3 may be installed in the grooves 4. For example, a first Z-axis magnetic detection mechanism may be installed in some of the grooves 4, a second Z-axis magnetic detection mechanism may be installed in some of the grooves 4, and a third Z-axis magnetic detection mechanism may be installed in some of the grooves 4. Specifically, the first X-axis magnetic detection mechanism is located between the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the first Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. The second X-axis magnetic detection mechanism is located between the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism, separating two adjacent grooves 4 corresponding to the second Z-axis magnetic detection mechanism and the third Z-axis magnetic detection mechanism. In the third Z-axis magnetic sensing mechanism, the first Z-axis magnetoresistive strip 3a is adjacent to the first X-axis magnetic sensing mechanism, and the second Z-axis magnetoresistive strip 3b is adjacent to the second X-axis magnetic sensing mechanism. The first Z-axis magnetoresistive strip 3a and the second Z-axis magnetoresistive strip 3b in the corresponding groove 4 extend in the Y-axis direction, and each of the first X-axis magnetoresistive strips 1a and each of the second X-axis magnetoresistive strips 1b extend in the Y-axis direction. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent first X-axis magnetoresistive strip 1a and first Z-axis magnetoresistive strip 3a. A pseudo-magnetic resistance strip 123 without a Wheatstone bridge may be provided between adjacent second X-axis magnetoresistive strip 1b and second Z-axis magnetoresistive strip 3b.

[0053] The magnitude of the external magnetic field changes the magnetization direction of the magnetoresistive strip, thereby changing the angle between the working electrode and the magnetoresistive strip. That is, the angle between the current direction in the magnetoresistive strip and the magnetization direction of the magnetoresistive strip corresponds to the magnitude of the external magnetic field. Each magnetic sensing mechanism is combined to form an independent Wheatstone bridge, and each arm of each Wheatstone bridge consists of at least one magnetoresistive strip. In one embodiment, several magnetoresistive strips with the same induction change upon sensing an external magnetic field constitute the arms of a Wheatstone bridge, and one Wheatstone bridge consists of two pairs of arms whose resistance value increases in response to the input of an external magnetic field and two pairs of arms whose resistance value decreases in response to the input of an external magnetic field (see Figures 6 to 9).

[0054] In one embodiment of the present application, a set / reset coil 6 is arranged above and / or below each magnetoresistive strip to generate a magnetic field in the direction of the easy axis of magnetization, and a working electrode is arranged on the upper and / or lower surface of the magnetoresistive strip, forming a predetermined angle with the magnetoresistive strip.

[0055] The set / reset coil 6 determines the initial magnetization direction of the magnetoresistive strip, and the power, ground, and electrode structure of the Wheatstone bridge above the magnetoresistive strip determine the current direction in the magnetoresistive strip. In the initial state, the ideal angle between the initial magnetization direction and the current direction may be 45° (although other values ​​are possible). In the presence of an external magnetic field, the external field changes the magnetization direction of the magnetoresistive strip, thereby changing the angle between the magnetization direction of the magnetoresistive strip and the current direction in the magnetoresistive strip. As the angle increases, the resistance of the magnetoresistive strip decreases, and as the angle decreases, the resistance of the magnetoresistive strip increases.

[0056] The self-detection coil 5 may be arranged in a partial area depending on the magnetic field to be detected by the magnetoresistive strip. The self-detection coil 5 generates a magnetic field in a detection direction corresponding to the magnetoresistive strip.

[0057] In one embodiment of the present application, a pseudo-magnetic resistance strip that does not output a signal in an external magnetic field is disposed between adjacent magnetic resistance strips. A working electrode is disposed on the upper and / or lower surface of the pseudo-magnetic resistance strip, forming a predetermined angle with the pseudo-magnetic resistance strip. Of course, the working electrode may not be disposed at a predetermined angle with the pseudo-magnetic resistance strip.

[0058] The present application further discloses a method for manufacturing a three-axis magnetic sensor, the method including the following steps: Step S1: A silicon substrate or a substrate having a circuit is provided. Step S2: Form at least two grooves on the surface of the substrate, each having a sidewall that forms a predetermined angle with the surface of the substrate. The grooves are arranged side by side along a first direction or a second direction, or partly along the first direction and partly along the second direction, and a mounting space is provided between at least one pair of adjacent grooves among the grooves arranged side by side in the first direction, and / or a mounting space is provided between at least one pair of adjacent grooves among the grooves arranged side by side in the second direction. Step S3: An insulating layer is formed on the surfaces of the substrate and the grooves. Step S4: Form a first magnetic detection mechanism and a second magnetic detection mechanism on the surface of the insulating layer of the substrate, and a third magnetic detection mechanism on the surface of the insulating layer of the groove, wherein at least one first magnetic detection mechanism is installed in a mounting space along a first direction and / or at least one second magnetic detection mechanism is installed in a mounting space along a second direction, and each of the first magnetic detection mechanism, the second magnetic detection mechanism, and the third magnetic detection mechanism includes a magnetic material. Each first magnetic detection mechanism detects a magnetic field in the first direction, each second magnetic detection mechanism detects a magnetic field in the second direction, and each third magnetic detection mechanism detects a magnetic field in a third direction. The first direction and the second direction form a plane corresponding to the surface of the substrate, and the third direction intersects with the surface of the substrate.

[0059] In one embodiment, the first direction is the X-axis direction of the coordinate system, and the first magnetic sensing mechanism is an X-axis magnetic sensing mechanism, the second direction is the Y-axis direction of the coordinate system, and the second magnetic sensing mechanism is a Y-axis magnetic sensing mechanism, and the third direction is the Z-axis direction of the coordinate system, and the third magnetic sensing mechanism is a Z-axis magnetic sensing mechanism.

[0060] In one embodiment of the present application, the magnetic material is any one selected from an anisotropic magnetoresistive material, a giant magnetoresistive material, and a tunnel magnetoresistive material, and when forming the magnetic material, a magnetic field is simultaneously applied to the substrate and annealed to induce the magnetization direction of the magnetic material and enhance the magnetic properties of the magnetic material.

[0061] In one embodiment of the present application, after step S4, the method further includes the following steps: Step S41: A dielectric layer is formed on the surface of the magnetic material of the first magnetic detection mechanism, the second magnetic detection mechanism, and the third magnetic detection mechanism. Step S42: A through hole is formed in the dielectric layer on the surface of the magnetic material. Step S43: A continuous electrode layer is formed on the surface of the substrate and on the sidewalls of the grooves. Step S44: The electrode layer is patterned to form a working electrode on the surface of the magnetic material, and the magnetic material contacts the working electrode to be formed later through the through-hole formed in the dielectric layer on its surface.

[0062] The manufacturing method may further include one or more of the following steps: Lead terminals are provided on the surface of the substrate and on both ends of the magnetoresistive strip in the groove. A self-detection coil is placed at the bottom of the groove, below the substrate, and below the magnetic detection mechanism. A set coil and / or a reset coil are placed at the top of the groove, above the substrate, and above the magnetic detection mechanism.

[0063] As described above, the three-axis magnetic sensor and the manufacturing method thereof proposed in this application can reduce process machining errors, widen the process window, and improve the overall yield of the product.

[0064] The technical features of the embodiments described above can be combined in any way. For the sake of simplicity, not all possible combinations of the technical features are described, but as long as there is no contradiction in the combination of these technical features, it falls within the scope of this specification.

[0065] The descriptions and applications of the present application are illustrative and are not intended to limit the scope of the present application to the above-described examples. Effects or advantages associated with the examples may be hindered by various factors and may not be realized in the examples, and the description of effects or advantages does not limit the examples. The embodiments disclosed herein are susceptible to modification and alteration, and various replacements and equivalent parts for the embodiments are known to those skilled in the art. Those skilled in the art may realize the present application in other forms, structures, arrangements, proportions, and with other components, materials, and parts without departing from the spirit and principles of the present application. Other variations and modifications may be made to the embodiments disclosed herein without departing from the scope and spirit of the present application.

Claims

1. A substrate having a surface along a plane defined by a first direction and a second direction perpendicular to the first direction, and having at least two grooves formed thereon, each having a trapezoidal cross section and opening onto the surface and consisting of two opposing inclined surfaces and a bottom surface connecting the two inclined surfaces; at least one first magnetic sensing mechanism that senses a magnetic field in the first direction; at least one second magnetic sensing mechanism that senses a magnetic field in the second direction; at least two third magnetic detection mechanisms that detect a magnetic field in a third direction orthogonal to the first direction and the second direction; the first magnetic sensing mechanism includes at least one first magnetoresistive strip extending in the second direction, the first magnetoresistive strips forming a first Wheatstone bridge; the second magnetic sensing mechanism includes at least one second magnetoresistive strip extending in the first direction, the second magnetoresistive strips forming a second Wheatstone bridge; the third magnetic detection mechanism includes at least one third magnetoresistive strip extending along the first direction or the second direction, and the third magnetoresistive strips form a third Wheatstone bridge; The grooves are all arranged in the first direction, or all arranged in the second direction, or some arranged in the first direction and some arranged in the second direction, the first magnetic detection mechanism and the second magnetic detection mechanism are installed on the surface of the substrate other than the grooves, and the third magnetic detection mechanisms are installed on the slopes of the grooves so as to correspond one-to-one to the grooves; At least one pair of adjacent grooves among the grooves arranged in parallel along the first direction are separated by at least one first magnetic detection mechanism, and / or at least one pair of adjacent grooves among the grooves arranged in parallel along the second direction are separated by at least one second magnetic detection mechanism. A three-axis magnetic sensor.

2. A magnetic resistance strip that does not constitute the first Wheatstone bridge, the second Wheatstone bridge, or the third Wheatstone bridge is provided between the adjacent first and third magnetic resistance strips, and / or a magnetic resistance strip that does not constitute the first Wheatstone bridge, the second Wheatstone bridge, or the third Wheatstone bridge is provided between the adjacent second and third magnetic resistance strips.

2. The three-axis magnetic sensor according to claim 1.

3. Coils are arranged above and / or below the first magnetic resistance strip, the second magnetic resistance strip and the third magnetic resistance strip, to generate magnetic fields in the easy magnetization direction of the first magnetic resistance strip, which is the same direction as the extension direction of the first magnetic resistance strip, the easy magnetization direction of the second magnetic resistance strip, which is the same direction as the extension direction of the second magnetic resistance strip, and the easy magnetization direction of the third magnetic resistance strip, which is the same direction as the extension direction of the third magnetic resistance strip, thereby determining the initial magnetization directions of the first magnetic resistance strip, the second magnetic resistance strip and the third magnetic resistance strip, Each of the first, second and third magnetoresistive strips has an elongated shape when viewed from the front surface side of the substrate, and a working electrode whose longitudinal direction forms a predetermined angle with the extending direction of the magnetoresistive strip is disposed on the upper and / or lower surface of the magnetoresistive strip.

2. The three-axis magnetic sensor according to claim 1.

4. Each arm of the first Wheatstone bridge is composed of at least one of the first magnetoresistive strips; In each arm of the first Wheatstone bridge, the first magnetoresistive strips of the same arm have the same induction change when detecting an external magnetic field, and the first Wheatstone bridge includes two arms whose resistance value increases in response to the input of the external magnetic field, and two arms whose resistance value decreases in response to the input of the external magnetic field; each arm of the second Wheatstone bridge is composed of at least one second magnetoresistive strip; In each arm of the second Wheatstone bridge, the second magnetoresistive strips of the same arm have the same induction change when detecting an external magnetic field, and the second Wheatstone bridge includes two arms whose resistance value increases in response to the input of the external magnetic field, and two arms whose resistance value decreases in response to the input of the external magnetic field; each arm of the third Wheatstone bridge is composed of at least one third magnetoresistive strip; In each arm constituting the third Wheatstone bridge, the third magnetoresistive strips of the same arm have the same induction change upon detecting an external magnetic field, and the third Wheatstone bridge includes two arms whose resistance value increases in response to the input of the external magnetic field and two arms whose resistance value decreases in response to the input of the external magnetic field.

2. The three-axis magnetic sensor according to claim 1.

5. A self-detecting coil is arranged below the first magnetic resistance strip, the second magnetic resistance strip and the third magnetic resistance strip, generating a magnetic field in a detection direction corresponding to each of the first magnetic resistance strip, the second magnetic resistance strip and the third magnetic resistance strip.

2. The three-axis magnetic sensor according to claim 1.

6. A step of providing a silicon substrate or a substrate having a circuit as a substrate having a surface along a plane defined by a first direction and a second direction perpendicular to the first direction; forming at least two grooves in the substrate, the grooves having a trapezoidal cross section, the grooves being open to the surface of the substrate and consisting of two inclined surfaces that form a predetermined angle with the surface of the substrate and a bottom surface that connects the two inclined surfaces, the grooves being all arranged side by side along the first direction, or all arranged side by side along the second direction, or some arranged side by side along the first direction and some arranged side by side along the second direction, and a mounting space being provided between at least a pair of adjacent grooves among the grooves arranged side by side in the first direction, and / or a mounting space being provided between at least a pair of adjacent grooves among the grooves arranged side by side in the second direction; forming an insulating layer on the surface of the substrate other than the groove and on the slope and bottom surfaces of the groove; forming a first magnetic detection mechanism and a second magnetic detection mechanism on a surface of the insulating layer at a surface of the substrate other than the groove, and forming a third magnetic detection mechanism on the surface of the insulating layer at the inclined surface of the groove so as to extend in the same direction as the extension direction of the groove, at least one of the first magnetic detection mechanism being installed in an installation space along the first direction and / or at least one of the second magnetic detection mechanism being installed in an installation space along the second direction, and each of the first magnetic detection mechanism, the second magnetic detection mechanism and the third magnetic detection mechanism including a magnetic material. A method for manufacturing a three-axis magnetic sensor.

7. forming a dielectric layer on a surface of the magnetic material of the first magnetic sensing mechanism, the second magnetic sensing mechanism, and the third magnetic sensing mechanism; forming a through hole in the dielectric layer on the surface of the magnetic material; forming a continuous electrode layer on the dielectric layer on the surface of the substrate other than the groove and on the slope of the groove so as to cover the dielectric layer; and forming a working electrode on the surface of the magnetic material by patterning the electrode layer so that the magnetic material contacts the working electrode, which is formed after the dielectric layer is formed, through the through-holes formed in the dielectric layer on the surface of the magnetic material. The method according to claim 6 .

8. the magnetic material is any one selected from an anisotropic magnetoresistive material, a giant magnetoresistive material, and a tunnel magnetoresistive material; When forming the magnetic material, a magnetic field is simultaneously applied to the substrate and annealed to induce the magnetization direction of the magnetic material and enhance the magnetic properties of the magnetic material. The method according to claim 6 .

Images